The objective of this project is to investigate the stepwise biosynthesis of the peptidoglycan-polysaccharide complex in Streptococcus sanguis and other cariogenic streptococci. It is hoped that a common presursor could be identified and utilized for the control of these bacteria. In this proposed budget period, the following scientific aspects will be investigated: a. The fine structure of cell wall polysaccharide. b. The role of galactose-lipid in the type specific antigen synthesis of cariogenic bacteria. c. The role of galactose polymers in the adherence of cariogenic bacteria to solid surfaces.